"Instead of winning by a few bike-lengths I only won by one bike-length today, which shows how tired I am," said Cavendish. "I'm glad I could do it for my team-mates because they've worked so hard for me in the last couple of weeks."

Cadel Evans finished further back, but still hangs on to the yellow jersey, just one second ahead of Frank Schleck.

Cavendish has now proved himself to be one of the most devastating sprinters on the Tour, and if he hangs on until Paris, has a great opportunity to record victory No4.

Meanwhile Ricco, who was the holder of both the polka-dot and white jerseys, for the race's leading climber and youth rider respectively, was taken off the Saunier-Duval team bus by police this morning after becoming the third rider to test positive for a banned substance in the 2008 race, following the Spaniards Moisés Dueñas Nevado and Manuel Beltran.

"It's for the same product as the other two," said the French anti-doping agency president, Pierre Bordry.

"It's completely shocking," said the International Cycling Union president Pat McQuaid. "It would strike me now that someone would have advised those guys to take some form of EPO thought to be undetectable because we haven't caught guys in this fashion for a long time."

The Italian was considered as a potential star of the sport and had finished second in this year's Giro d'Italia. But now he faces a lengthy ban - and possibly worse.